Cancer is increasingly recognized as an important complication of HIV infection, with -10% of HIV-infected persons expected to develop cancer at some point in their lifetime. For many HIV-associated malignancies (HIVAM), few good strategies for prevention or treatment exist. Seattle has developed an extraordinary community of researchers in both cancer and HIV, and over the last five years the AIDS-Associated Infections and Malignancies (AAlMs) Scientific Working Group has been highly successful in bringing together these research communities to address HIVAM. We now propose to expand the activities of the AAlMs group to become a Core in the UW/FHCRC CFAR, with three Specific Aims: 1) Enable studies of HIVAM through the development and deployment of assays for the molecular detection and quantification of viral oncogens; 2) Facilitate the diagnosis of HIVAM, as well as detailed studies of HIVAM pathogenesis, in CFAR-affiliated HIV cohorts through the provision of a suite of molecular and immunohistochemical tumor assays; 3) Disseminate data instruments to accurately identify and characterize cancer endpoints among HIV-infected persons participating in CFAR-affiliated research studies. To achieve these goals, we have assembled a group of international experts from the Fred Hutchinson Cancer Research Center and the University of Washington to serve on the Core's Steering Committee, leveraged the highly successful Molecular Diagnostics Laboratories in Seattle and Uganda, expanded core pathology diagnostic services offered by the Hutchinson Center and the Seattle Cancer Care Alliance, and utilized the expertise in data collection of the Statistical Center for HIV/AIDS Research & Prevention.